This is a very interesting topic. I personally like to know all the routes, road maps, etc. when I travel. Since I travel to Nainital at least 10 times in a year, and that I know most of the routes (if not all), thought I could be a good resource in drawing a route map of Delhi to Nainital.
There are basically 02 routes that you can take while going to Nainital from Delhi. Both the routes run on the same track up to Moradabad and then deviate after Moradabad. One of the routes is via Kaladungi and the other goes through Rampur. Let me explain you both the routes going to Nainital:
Delhi to Nainital through Rampur: Delhi - Ghaziabad - Hapur - Garmukteshwar - Gajraula - Moradabad - Rampur - Haldwani - Kathgodam - Nainital
Delhi to Nainital through Kaladungi: Delhi - Ghaziabad - Hapur - Garmukteshwar - Gajraula - Moradabad - Tanda - Bazpur - Kaladungi - Nainital
Via Rampur: Rampur route is fine up-to Moradabad but the major hassle comes while you are crossing Rampur. You have to cross the busy bazaars of Bilaspur and Rampur to get to Haldwani, which is even more crowded. From light to heavy vehicles to bullock carts, you ll have to go through a lot of traffic and dirty roads. Definitely not recommended.
Via Kaladungi: The beauty of this route lies in the fact that this road is meant for only light vehicles. This further sums up the fact that there would not be too many heavy vehicles passing by and that you are pretty much safe on the road 
The road condition is absolutely fantastic and the total distance is only 290 kms. You can easily reach Nainital in not more than 6 - 7 hours. Definitely recommended!
Moradabad - Nainital Road Map (Via Kaladungi):
After crossing the Moradabad bypass, take a left U turn (the right turn will go to Rampur) for Corbett National Park. Keep following the road and it will take a right turn on its own (passing through a small bazaar) and then after going for about 8 kms more, you will see a right turn pointing Bazpur. Take this right turn and keep going straight for Bazpur (landmark: Bazpur Gurudwara just after the rail track) and then straight on for Kaladungi (passing through a jungle). On reaching Kaladungi (after crossing a small bridge and going 200 meters ahead) you will see a board pointing left for Nainital. After taking this right turn you will start climbing up (after 5 kms) and now you are only 30 kms short of Nainital. Yes boss…You are done in just 290 kms from Delhi!
Caution:Please do not take this route (or try and research) during July and August. The bridge in Tanda collapses every year during monsoons. You could also drop us a mail and we will certainly try and find out for you guys
Please let us know what you think about this route and if you have any other information for us.
